A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. including part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Conventional lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
In lithography, high power electric motors, such as planar motors are used, for example to enable a substrate table that holds the substrate, or a support that holds a pattering device, to be moved. On the one hand, the high accelerations require powerful motors. On the other hand, powerful motors involve a high weight of a moving part, which adversely affects a maximum acceleration to be achieved due to the higher mass of the structure to be moved. Furthermore, compliance plays a role. In case a plurality of motor units are applied, for example a motor unit to propel in an x direction and a motor unit to propel in an y direction, a compliance of a structure that interconnects the motor units may limit a maximum bandwidth and dynamic performance of movements to be achieved.